Single-spin asymmetries in inclusive charged pion production by transversely polarized antiprotons

Abstract

The analyzing power AN in inclusive π− and π+ production has been measured with a 200 GeV/c transversely polarized antiproton beam over a wide xF range (0.2 ≤ xF ≤ 0.9) and at moderate pT(0.2 ≤ pT ≤ 1.5GeV/c). The asymmetry AN increases with increasing xF from zero to large positive values for π−′S, and decreases from zero to large negative values for π+′S. A threshold for the onset of the asymmetry is observed about pT ∼ 0.5 GeV/C, below which AN is essentially zero and above which AN ncreases (decreases) with pT for π−′S (π+′S) in the covered pT range. © 1996 The American Physical Society.